(A) (Top) Transfer of allogeneic T cells into B7-H3–deficient animals leads to an increased GVHD lethality compared with the transfer of wild-type T cells. (Bottom) Transfer of B7-H3–deficient T cells into recipient animals results in stronger GVHD than transfer of wild-type T cells. (B) Because a delayed transfer of B7-H3–deficient lymphocytes is not associated with enhanced GVHD, these results indicate that blockade of B7-H3 during DLI might be a therapeutic measure to enhance GVL effects. Professional illustration by Patrick Lane, ScEYEnce Studios.